I treated one hive with OAV: sealed entrance with cloth, 2.5 min. heating, then 2 min. with power off, then removed the vaporizer and sealed the hive for 10 more mins. After I opened the entrance, 20-25 bees and a drone ran out and flew right away like it was noon, even though it was a 55°F windy late night. Only two dead bees. I use a slatted rack for less heat exposure to the bees. Is it normal to have a patch of OA hoar frosting on the slat right above the vaporizer and some (OA) flakes on top of the inner cover. Should do I remove it ASAP? (I removed shims from underneath the inner cover for the OAV procedure.) I used 2 grams of OA (Savogran). Should I reduce the dose or the vap time? Would appreciate any comment and sharing your experience. Thanks, h.